In recent years, research and development in how to dispose an object having various specific functions on an inner surface of a pneumatic tire have been performed.
For example, attaching methods have been proposed in which a tire tag (radio frequency identification tag), a chip, a sound absorbing member, or the like is attached to an inner liner or the like of a green tire using a so-called surface fastener, such as a hook and loop fastener or a hook and hook fastener (Japanese Unexamined Patent Application Publication Nos. 2005-517581A and 2006-44503A).
The surface fasteners proposed in Japanese Unexamined Patent Application Publication Nos. 2005-517581A and 2006-44503A are preferred in that the surface fasteners exhibit relatively strong engagement force when attached and achieve engagement on a surface regardless of slight misalignments during the attaching operation. However, when subjected to high speed rolling motion at relatively high temperatures, the tire inner surface deforms and compacts repeatedly over an extended period of time at high speeds, resulting in partial physical deterioration in the surface fastener. As this deterioration progresses, the engagement force of an entirety of the surface fastener deteriorates/declines over time. This leads to difficulties in retaining a desired engagement force over an extended period of time.
The present inventor et al. proposed pneumatic tires each having one fastener in a separable pair of mechanical fasteners, on a tire inner surface (Japanese Unexamined Patent Application Publication Nos. 2012-25318A and 2012-240465A). These pneumatic tires are essentially free of the aforementioned problems and in particular, the obtained engagement force is great and is essentially free of variations (positional variation within the tire and variation from tire to tire). Furthermore, the engagement force deteriorates/declines minimally over time even under extreme usage conditions including repetitive deformation and compaction of the tire inner surface caused by high speed tire rolling motion at relatively high temperatures over an extended period of time, and the desired engagement force can be retained over an extended period of time.
Approaches using this mechanical fastener are superior from the perspectives of the obtained engagement force, variations in the engagement force, reliability in the engagement operation, and the like. As a method for attaching the one fastener to the tire inner surface, the present inventor et al. proposed individually embedding the fasteners in a tread rubber and vulcanizing the tire, and disposing the one mechanical fastener in the separable pair of mechanical fasteners on the tire inner surface. The one mechanical fastener is composed of at least two fastener components that are fixed together while sandwiching a rubber layer being a tire component, or a rubber-coated fiber reinforced member to dispose the one mechanical fastener (Japanese Unexamined Patent Application Publication No. 2012-25318A).
The present inventor et al. also proposed disposing the one fastener in the pair of mechanical fasteners on the tire inner surface by fixing the at least two fastener components together while sandwiching a woven fabric or nonwoven fabric made of fibers (Japanese Unexamined Patent Application Publication No. 2012-240465A).
However, with these methods, the desired attachment strength may not be obtained depending on the shape and attaching position of the mechanical fastener, and accordingly, the durability and long lifetime of the pneumatic tire provided with an object having a specific function may not be achieved as desired.
The mechanical fastener is required to have a greater attachment strength and a longer lifetime to be suitable for characteristics (weight, size, shape, and the like) unique to the object having a specific function and disposed in the tire.